CKA Container Fundamentals 3

Question 1

Which signal does Docker send to a container process by default when stopping a container with 'docker stop'?

Accepted Answer

SIGTERM

Answer

Docker sends SIGTERM first to allow the process to shut down gracefully, then sends SIGKILL after the stop timeout if the process hasn't exited.

Question 2

What is a container's PID 1 significant for?

Accepted Answer

PID 1 receives signals and is responsible for reaping zombie processes

Answer

PID 1 in a container receives signals sent to the container and must properly handle signal forwarding and reaping zombie child processes to avoid resource leaks.

Question 3

What is the effect of setting 'imagePullPolicy: Never' on a Kubernetes Pod?

Accepted Answer

Kubernetes only uses a locally cached image and fails if not found

Answer

With imagePullPolicy: Never, Kubernetes will not attempt to pull the image from a registry and will fail if the image is not already present on the node.

Question 4

Which container runtime interface (CRI) component is responsible for managing image storage on a node?

Accepted Answer

containerd's image service

Answer

The CRI image service, implemented by runtimes like containerd, handles pulling, listing, removing, and managing image layers on the node.

Question 5

What does a non-zero exit code from a container's main process indicate to Kubernetes?

Accepted Answer

The container exited with an error, potentially triggering a restart

Answer

A non-zero exit code signals failure; depending on the pod's restartPolicy, Kubernetes may restart the container to recover from the error.

(CKA) Certified Kubernetes Associate Practice Test

(CKA) Certified Kubernetes Associate Practice Test

CKA Container Fundamentals 3